In tests conducted for the newspaper a chemical removed from children's pajamas because of cancer concerns in the late 1970s was found in 11 baby mattresses sold recently under the Babies R Us, Foundations and Angeles brands, the Tribune said.
"These are bad chemicals, and we've known they've been bad for a long time," Linda Birnbaum, director of the federal government's National Institute of Environmental Health Sciences, told the newspaper. "If these chemicals are in your child's mattress, they are going to be constantly exposed."
Birnbaum, a toxicologist, said regulators had told her the chemical chlorinated tris and other toxic flame retardants were not being used in mattresses.
Of the 27 mattresses tested, all of the those found to contain chlorinated tris had labels saying they were made in China or imported from China, the Tribune said.
None of the tested mattresses made in the United States contained any significant amounts of any form of chlorinated tris, it said.
One importer vigorously defended its mattresses.
Summer Infant Inc., the importer of the Babies R Us branded mattresses with chlorinated tris, noted the mattresses "are in a sealed impermeable plastic covering," which "ensures no exposure of the inner mattress foam to the child."
But Birnbaum expressed skepticism whether any foam product can be sealed completely, suggesting chemicals can escape as vapors through seams or holes.